Effect of Essential Oils on Aeromonas hydrophila in a Culture Medium and in Cooked Pork

Abstract

The inhibitory effects of essential oils of coriander, clove, nutmeg, and pepper towards Aeromonas hydrophila were studied in tryptic soy agar. Essential oils of clove, coriander, and nutmeg at concentrations of 500, 1,250, and 10,000 μg/ml, respectively, were effective in inhibiting the growth of A. hydrophila on tryptic soy agar. Pepper was the least active oil of which 15,000 μg/ml appeared to inhibit only a diluted culture of A. hydrophila. Behavior of A. hydrophila was also evaluated in samples of noncured cooked pork treated either with coriander or clove oil. Meat samples were packaged either under vacuum or air and stored at 2 and 10°C. Both essential oils caused a marked reduction of A. hydrophila number. In the meat samples treated with clove oil and stored at 10°C, the lethal effect was significantly enhanced by the vacuum packaging. These data suggest that essential oils of coriander and clove could be used to control the hazard of A. hydrophila in noncured cooked meat at low and increased temperatures, especially in combination with vacuum packaging.